Stephen Hawking thought an asteroid impact posed the greatest threat to life on Earth. Thanks to Kiwico for sponsoring this video. For 50% off your first month of any crate, go to https://kiwico.com/veritasium50 For other potential world ending catastrophes, check out Domain of Science: https://ve42.co/DoS Special thanks to: Prof. Dave Jewitt from UCLA Earth, Planetary, and Space Sciences Prof. Mark Boslough from Sandia National Labs Scott Manley: null Ryan Wyatt at Morrison Planetarium Prof. Amy Mainzer Alexandr Ivanov for the opening shot of Chelyabinsk Meteor Maps of Asteroid Impacts —https://ve42.co/Map Time passing animation from Universe Sandbox - http://universesandbox.com/ Opposition Effect — https://ve42.co/Belskaya2000 Belskaya, I. N., & Shevchenko, V. G. (2000). Opposition effect of asteroids. Icarus, 147(1), 94-105. Potentially Hazardous Asteroids — https://ve42.co/Perna2013 Perna, D., Barucci, M. A., & Fulchignoni, M. (2013). The near-Earth objects and their potential threat to our planet. The Astronomy and Astrophysics Review, 21(1), 65. Survey of Potentially Hazardous Asteroids — https://ve42.co/NEOSurvey Population Vulnerability — https://ve42.co/Rumpf2017 Rumpf, C. M., Lewis, H. G., & Atkinson, P. M. (2017). Population vulnerability models for asteroid impact risk assessment. Meteoritics & Planetary Science, 52(6), 1082-1102. Size distribution of NEOs — https://ve42.co/Trilling17 Trilling, D. E., Valdes, F., Allen, L., James, D., Fuentes, C., Herrera, D., ... & Rajagopal, J. (2017). The size distribution of near-earth objects larger than 10 m. The Astronomical Journal, 154(4), 170. 2020 NEOWISE Data Release — https://ve42.co/NEOWISE National Research Council Report— https://ve42.co/Defending Board, S. S., & National Research Council. (2010). Defending planet earth: Near-Earth-Object surveys and hazard mitigation strategies. National Academies Press. Tug Boat — https://ve42.co/Schweickart03 Schweickart, R. L., Lu, E. T., Hut, P., & Chapman, C. R. (2003). The asteroid tugboat. Scientific American, 289(5), 54-61. Gravity Tractor 1 — https://ve42.co/Lu05 Lu, E. T., & Love, S. G. (2005). Gravitational tractor for towing asteroids. Nature, 438(7065), 177-178. Laser Ablation — https://ve42.co/Thiry14 Thiry, N., & Vasile, M. (2014). Recent advances in laser ablation modelling for asteroid deflection methods. SPIE Optical Engineering+ Applications, 922608-922608. Yarakovsky Effect — https://ve42.co/Yara DART Mission — https://ve42.co/DART Nuclear 1 — https://ve42.co/Ahrens92 Ahrens, T. J., & Harris, A. W. (1992). Deflection and fragmentation of near-Earth asteroids. Nature, 360(6403), 429-433. Nuclear 2 — https://ve42.co/Bradley10 Bradley, P. A., Plesko, C. S., Clement, R. R., Conlon, L. M., Weaver, R. P., Guzik, J. A., ... & Huebner, W. F. (2010, January). Challenges of deflecting an asteroid or comet nucleus with a nuclear burst. In AIP Conference Proceedings (Vol. 1208, No. 1, pp. 430-437). American Institute of Physics. Researched and Written by Petr Lebedev, Jonny Hyman and Derek Muller 3D animations, VFX, SFX, Audio Mixing by Jonny Hyman 2D animation by Ivy Tello Intro animation by Nicolas Pratt With Filming by Raquel Nuno Music from https://epidemicsound.com/ "Stellar Dance" "Orbit" "That Notebook" "What We Discovered" "Out of Poppies" "Handwriting" Images and video supplied by Getty Images